I have Zotero installed on the old iBook and it’s integration with MS Word v.X for Mac is quite painless and seems to work well. Certainly I think it’d be useful for working on shorter documents (essays, articles and chapters) providing you were using a common citation style.

Of interest particularly to biblical scholars is Zotero Forums - Using Zotero with the Society of Biblical Literature (SBL) style. SBL with EndNote is supported (see here), though it is only for versions later than EndNote 9, I think.

See also:

• Greenflame · MS Word’s native bibliography/citation handling?
• Greenflame · Thinking about writing tools